Light-sensitive silver halide photographic materials can form images with a high sensitivity and a high resolution, and hence they are put in wide use. As an example of their use, they are used in the field of X-ray photography. Images of tissues and skeletons of patients can be obtained by irradiating the related part of a patient with X-rays, and exposing to the rays having transmitted therethrough a photographic element comprising a blue-colored transparent film support provided thereon with at least one light-sensitive silver halide photographic emulsion layer.
Meanwhile, plastic films so strongly tend to be statically charged that their use is greatly restricted in many instances. For example, in the case of X-ray light-sensitive silver halide photographic materials, supports made of polyethylene terephthalate are commonly used, which tend to be statically charged in an environment of low humidity as in the winter to cause many difficulties. In particular, the most important difficulties are static marks which may form as a result of release of charges stored before photographic processing. This results in an entire loss of commercial values of photographic films. In particular, in the case of X-ray light-sensitive silver halide photographic materials for medical use or industrial use, the worst may result such that a very dangerously wrong judgement is made. Thus, when X-ray light-sensitive silver halide photographic materials are designed, it is the most important subject to keep static marks from occurring.
Formation of static marks causes a serious damage on images also in the case of light-sensitive materials other than the X-ray light-sensitive silver halide photographic materials, for example, monochromatic light-sensitive photographic materials such as light-sensitive materials for graphic arts, and light-sensitive materials for color photography, and it is sought for them to be kept from occurrence of static marks.
The best way to keep static marks from forming is to raise conductivity of substances so that static charges can be escaped in a short time before the charges accumulated are released. Accordingly, methods for raising conductivity of supports or various types of surface layers of light-sensitive photographic materials have been hitherto proposed, and it has been attempted to use various types of moisture-absorptive substances and water-soluble inorganic salts, certain kinds of surface active agents, polymers, and so forth. Many of these substances exhibit specificities depending on the types of film supports and the differences in photographic composition and can produce good results on certain types of film supports and photographic emulsions or other photographic components. However, they not only can be of no use to antistatic on different types of film supports and photographic components, but also may adversely affect photographic performances. As additional important disadvantages of many of these substances, their conductivity has a moisture dependence, resulting in a loss of functions as conductive layers in an environment of low humidity.
For the purpose of better preventing such deterioration of performances in an environment of low humidity, Japanese Patent Examined Publications No. 6616/1960 and No. 143431/1981 disclose techniques in which metal oxides are used as agents for antistatic treatment. The former discloses a method in which a colloidal sol dispersion is used. The latter discloses a method in which a powder with a high crystallinity is used after it has been treated at a high temperature so that the problem of an insufficient conductivity in the former can be overcome. When, however, the latter technique is used as a measure for light-sensitive photographic materials, there is a problem of light scattering because of the use of the powder with a high crystallinity, where its particle diameter, particle/binder ratios and so forth must be taken into account.
Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 62650/1983 discloses a technique in which a crystalline metal oxide is used as an antistatic agent, but there is no disclosure as to its relationship with static marks.